Progressive muscular atrophy and posterior dislocation of the humerus following electric shock.

A 34-year-old man received an electric shock (240 volts A.C.) in his right hand from a faulty domestic power drill, the current earthing through his left hand. Tetanic muscle spasm prevented him from releasing the drill for approximately 15 sec, causing severe pain in his neck and left shoulder. For several days he experienced muscle spasms throughout his left arm and neuralgic pain radiating down the lateral aspect of his left forearm and into his thumb. After 3 weeks, progressive weakness with muscle wasting developed in this limb and movement of his left shoulder became painfully restricted. On the day of the accident, he attended a Casualty Department where no clinical deficit was found. Reexamination 5 weeks later revealed weakness and wasting of the spinati, deltoid, triceps, biceps and brachioradialis -muscles with exaggerated tendon reflexes in the left arm and a positive left Hoffman's reflex in his left hand. There were no long tract signs in the lower limbs. Passive movements of his left shoulder were restricted, particularly internal and external rotation.